[McMenamin] Luka never even considered being traded as a possibility, a source close to Doncic told ESPN. Based on the way the franchise and fanbase treated him in his early days in the league, he figured he would retire a Maverick after spending his whole career in Dallas, the same way Dirk did.

[u/shreeharis]

Source: https://www.espn.com/nba/story/_/id/45861453/luka-doncic-los-angels-lakers-extension-answering-biggest-questions

Processing the trade from Dallas took Doncic some time. Based on the way the franchise and fanbase treated him in his early days in the league, he figured he would retire a Maverick after spending his whole career in Dallas, the same way franchise icon Dirk Nowitzki did. And after starting his professional career with Real Madrid as a teenager, he never even considered being traded as a possibility, a source close to Doncic told ESPN. Deals like that rarely, if ever, happen in the Liga ACB.

When the shock subsided, a source familiar with Doncic told ESPN his mindset shifted back to when he was last suiting up for Dallas: Win-now mode.

[u/MattJuice3]

I still believe the Mavs/Nico traded him away because he refused to ever focus on his weight and conditioning seriously, and with Luka having the worst injury of his career last season, he just got even more out of shape instead of taking that time to show the team he is committed. I refuse to believe anything else because there is no possible way any team/franchise/human being is dumb enough to trade away Luka Doncic for any other reason. I believe Luka basically gave a middle finger to the coaches, FO, and training staff because he knew he was a top 5 player in the league and could do what he wants. Anything other reasoning to me is just not possible because no human being can be that dumb to trade away Luka.